Avalanche Canada ghelgeson, Avalanche Canada

Cariboos Avalanche Forecast

Nov 25th, 2019 3:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Storm Slabs.

Riding quality is good, but storm slabs are sensitive to human triggering at and above treeline to size 2. Below treeline the new snow rests on a touchy layer of surface hoar, so steep unsupported features, rolls, creek bottoms and terrain traps are all suspect.

Summary

Confidence

Low - Uncertainty is due to the limited number of field observations.

Weather Forecast

After a stormy weekend we’re transitioning to clearing skies, colder temperatures and no significant precipitation for the foreseeable future.

MONDAY NIGHT: Freezing level at valley bottom, light variable breeze, no significant precipitation expected.

TUESDAY: Scattered cloud cover, freezing level at valley bottom, light east/northeast wind, no significant precipitation expected.

WEDNESDAY: Clear skies, freezing level at valley bottom, moderate east wind, no significant precipitation expected.

THURSDAY: Clear skies, freezing level at valley bottom, light east wind, no significant precipitation expected.

Avalanche Summary

We're flying nearly blind here with very limited observations, but we suspect there was a natural avalanche cycle Saturday night into Sunday. If you're out in the backcountry we desperately want to hear from you on the MIN

Snowpack Summary

Winter is slowly descending to the valleys with about 70 to 90 cm of snow at 1220 m and 90 to 160 cm at treeline. Cornices are reportedly bigger than normal for this time of year.

Our data suggests the weekend storm produced 20 to 60 cm of snow accompanied by strong west/southwest wind, but there could be bigger accumulations of storm snow in favored locations, we got a great MIN report Monday from the northern portion of the region. On steep south facing slopes in the alpine the new snow rests on a crust. A crust is also present on all aspects below 1600 m and many locations have surface hoar on top of the crust.

There are a variety of crusts in our young snowpack, but a problematic rain crust down about 50 to 100 cm is beginning to stand out. This "October Crust" is showing sudden & repeatable results when subjected to snowpack tests. Avalanches failing on this interface have the potential to be large and could easily surprise users who are getting out onto snow for the first time this season. There's a great "pre-storm" summary of conditions at Allan Creek here.

Problems

Storm Slabs

An icon showing Storm Slabs

Likelihood

Possible-Likely

Expected Size

1 - 2.5

Last weekend's storm produced 20 to 60 cm of snow accompanied by strong west/southwest wind forming widespread storm slabs. These slabs rest on a variety of weak layers which will likely keep them susceptible to human triggering this week, especially in bigger terrain near ridge crest. Caution below treeline too, although it's pretty shallow down there new snow may be resting on surface hoar.

Aspects:

All aspects.

Elevations:

All elevations.

Valid until: Nov 26th, 2019 5:00PM